Format with line length 110 to match flake8
make black part of linting check
Update travis spec for updated black requirements
Add diff output for black on failure
update changelog
On Python 3, response.msg.keys() contains the same value multiple times if
there are multiple headers with the same value. Work around this by
converting to a set before iterating over it.
Let's not use Google to test redirects since it changes depending on your
geographic location. I changed the test to use httpbin.org, since
a lot of our tests already depend on httpbin.org anyway.
Somedays, I'd like to implement my own local mock HTTP server I
can do asserts against. The test suite would just start it up,
and the server would record the requests, which I could then
retrieve and compare.
Closes#21
